I installed Garmin Express software to my computer and plugged in my GPS using a mini USB connection. Garmin Express recognized the device and gave me the option to register the GPS using an email address or skip to the next step. I skipped that part and went to the update process. After clicking “Install” some software was downloaded to the GPS. Then I was asked to disconnect the GPS and restart it before reconnecting back to the computer. Then the downloading took maybe 8 minutes. I did a second update to the software after the maps were updated so now when I start my GPS it says 2015 for the software and 2016 for my internal maps.
I did not see any option to update the maps I have on a microSD chip, so only INTERNAL maps can be updated this way (This is very easy compared to the process Garmin used a few years ago.)
For any external map updates, I have a feeling Garmin would like you to buy the newer version on a microSD card.